The present invention relates to a musical score recognition apparatus for optically reading a musical score sheet to form a two-dimensional image data, for analyzing the image data to recognize notes and other symbols, and for effecting an automatic musical performance based on recognized results. More particularly, the present invention relates to an image processing technology to realize comparative display of an original score and the recognized score, visual discrepancy indication therebetween, and visual notification of indefinite symbols which fails in recognition or interpretation.
For example, Japanese patent application laid-open No. 5-35924 discloses a score recognition apparatus operable to read a score print by an image scanner or else to form an original image data, and subsequently to recognize therefrom score elements such as notes and other symbols to produce a performance data such as Musical Instrument Digital Interface (MIDI) data. The score recognition apparatus analyzes the original image data obtained by reading the score sheet through the image scanner to carry out recognition of various score elements including staff lines, notes, sharp (.music-sharp.), flat (.music-flat.), rest, G clef and F clef. The conventional score recognition apparatus hardly achieves 100% of a recognition rate. Therefore, it is necessary to display the results of the score recognition in order to visually check the same to find a recognition error, and in order to correct a score data if necessary. In such a case, the recognized results and the original score must be visually compared with each other. However, the conventional score recognition apparatus is not constructed to facilitate the visual comparison.
The score recognition apparatus receives an original image data representative of a source score, and recognizes contents thereof to produce an automatic performance data, a print data or else. However, the conventional score recognition apparatus cannot achieve 100% of accuracy. Therefore, a user finally checks the recognized results to manually correct recognization errors. However, the conventional score recognition apparatus displays separately an inputted original score and a synthetic score reproduced according to the recognition results. Thus, the user must compare the original score and the synthetic score with each other to find a discrepancy therebetween, which would cause an overlook and a mistake in correction of the recognition results.
The conventional score recognition apparatus hardly achieves 100% of the recognition rate. Particularly, it is quite difficult to perfectly recognize a hand-written score sheet. Consequently, the reproduced score may contain indefinite score symbols which fail in recognition. However, the conventional apparatus is not constructed to visually indicate an existence of indefinite score elements to the user. Therefore, the user may inadvertently accept the recognized results as a perfect form even though indefinite score elements are actually involved. In addition, the recognition process of the score sheet requires a long time. The recognized results are displayed after the recognition process is completed throughout the whole of the original image data, hence the user disadvantageously waits for a long time from inputting of read score contents until visual outputting of the recognized results.